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Old 10-11-2019, 04:40 AM   #1
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Default Fuel Mileage

whats everyone getting for mileage in their trucks?
on top of that, what mods do you have that would change mileage?
rims and tires change lots, gear sets, weight? etc?

i got a couple more d21s and one of them i have been dailying for the past month and a bit. done a ton of maintenance and have been getting about 7ish km/L of fuel there abouts...which to me is terrible (my civic was 14km/L and was much faster than the truck lol)

oem sticker says it should be about 8.5km/L for city, which is mostly what i do, highway is stop and go so i count that as city. i have 215/75/15 tires on my OZs and no egr stuff. running 2degrees past stock timing, wider gap plugs, new o2. fuel pres and coolant temp seem to be in line with factory. doesnt have a cat, mild exhaust. the torque is great down low but i feel hits a wall more or less at 3500rpm, keeps going but noticeably slower? if that makes sense, like its being choked almost.
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Old 10-11-2019, 05:08 AM   #2
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My stock 91 4x4 extra cab gets about 8.5ish or 19-20mpg. Can't remember my tires size and too lazy to go look right now. I did put a lot of thought into my tires because of the lack of power on these engines. I also climb a lot of steep mountains so the gearing to tire size is important.
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Old 10-11-2019, 08:31 AM   #3
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Driving a good ute around with 1tonne in the back is the same or should be as nothing in the back, speed wise. That's what these trucks are for. Comparing it to a civic is not ideal. Anyway, my 88 is a carb stock in everything and runs 10 litres to the 100 in city and 15 on highway. My modified 91 runs 6 in city and 10 highway. Hope that gives some perspective. Long live litres BTW.
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Old 10-11-2019, 01:04 PM   #4
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There are a lot of threads on this if you search. If you drive these trucks like a bat out of hell they get crap fuel economy.



Try turning your timing back to stock. Might just solve both your problems. Fuel economy and performance changes can come about rapidly with small changes to timing.
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Old 10-11-2019, 02:27 PM   #5
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i did search before I posted. Found it odd I couldnt find a few recent ones before making this one..but anyways
when adding a bit of timing it tends to gain power and better fuel economy due to a better burn. i am going to pull plugs again and see how theyre doing. I had a weird situation where half the plug was normal/dark and the other side was white. looked like one of the valves wasnt opening on all 4 cyl, was really weird, and even weirder is theres no valvetrain noise to indicate as such.
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Old 10-11-2019, 03:36 PM   #6
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Incorrect. It can make a tiny bit of power with more timing but economy gains is a myth. I run 27 degrees of timing because that's where my motor was happiest. If it was happiest at 4 degrees I would have run it there. Any more or anything less it tanks in economy and the power delivery changes. Lower I have gunt but less go. Higher I have more go but a little less low end grunt.



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Old 10-11-2019, 05:38 PM   #7
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My 89 with auto got 15mpg with the ac off from the day it was new...
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Old 10-11-2019, 07:45 PM   #8
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Battleaxe? What configuration is your rig?



I have a VG33 with TBI, 27BTDC, manual tranny, 4.11 gears, 31x10.5 BFG KO2s, aluminum 15x7 wheels, long tube headers, roughly VG30 cam profiles best I can tell, and a ceramic clutch. I get about 19MPG on the highway. Way worse in town, probably 15ish or worse.



When I was mostly stock with a VG30i and long tubes I could do 25MPG on the highway.
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Old 10-12-2019, 01:42 AM   #9
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Quote:
Originally Posted by Deerhurst View Post
Battleaxe? What configuration is your rig?

I have a VG33 with TBI, 27BTDC, manual tranny, 4.11 gears, 31x10.5 BFG KO2s, aluminum 15x7 wheels, long tube headers, roughly VG30 cam profiles best I can tell, and a ceramic clutch. I get about 19MPG on the highway. Way worse in town, probably 15ish or worse.

When I was mostly stock with a VG30i and long tubes I could do 25MPG on the highway.
27degrees?!? more timing CAN yield better economy, theres a range in where the motor is most efficient and makes more power. more timing does not mean better mileage, i agree to that.

mine is basic, 261k kms, egr delete, emissions delete, cracked oem manifold (have a non cracked to go on) 055gap plugs, ngk wires, 17btdc timing iirc, coolant temp sensor i put in tested alright, new ngk o2, my oz aluminum rims but they're near solid lol, with 215/75/15 yoko geolander GO15s, stock rear end, stock trans etc. i run about 35-38psi in the tires so i have done next to nothing to try and "improve" the mileage, however trying to get it to "stock" mileage first. my old white truck didnt have a trip or tach, so i just filled it whenever it got low.
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Old 10-12-2019, 01:43 AM   #10
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Quote:
Originally Posted by mytmouz View Post
My 89 with auto got 15mpg with the ac off from the day it was new...
holy cow thats terrible :/
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